Full catalog/TOMSN7SO2
TOMSN7SO2·v3·dataset

Sulfur dioxide from volcanoes and pollution (Nimbus-7)

TOMS/N7 MS SO2 Vertical Column 1-Orbit L2 Swath 50x50 km V3 (TOMSN7SO2) at GES DISC
atmosphere NASA GES_DISC Level 2
In plain English

What it measures. The amount of sulfur dioxide gas in a column of air, a gas mainly released by volcanoes, power plants, refineries, and burning fossil fuels.

How it's made. Derived from ultraviolet light measurements by the TOMS instrument on NASA's Nimbus-7 satellite (1978-1993), reprocessed with a newer, more consistent algorithm.

How & where you'd use it. Used to study volcanic eruptions and human-caused pollution over a fifteen-year span, and to build a historical record of past eruptions. Near the surface this gas is toxic and causes acid rain.

What's measured

ATMOSPHERE › AIR QUALITY › SULFUR OXIDESATMOSPHERE › ATMOSPHERIC CHEMISTRY › SULFUR COMPOUNDSATMOSPHERE › ATMOSPHERIC CHEMISTRY › SULFUR COMPOUNDS › SULFUR DIOXIDEATMOSPHERE › ATMOSPHERIC CHEMISTRY › SULFUR COMPOUNDS › SULFUR OXIDESCLIMATE INDICATORS › PALEOCLIMATE INDICATORS › VOLCANIC ACTIVITYHUMAN DIMENSIONS › NATURAL HAZARDS › VOLCANIC ERUPTIONS

Coverage & cadence

  • Time span1978-11-01 → 1993-05-06
  • Measured byNimbus-7 (TOMS)
  • Processing levelLevel 2
  • Spatial extent-180, -90, 180, 90
  • StatusCOMPLETE

What you can do with it

  • Map air pollutants — NO₂, aerosols, ozone
  • Track greenhouse gases and Earth's energy budget
  • Feed weather and air-quality analysis
Official description

Version 3 is the current version of the data set. Older versions will no longer be available and have been superseded by Version 3. The goal of this data set is to create and archive a Level 2 SO2 Earth Science Data Record (ESDR) from backscatter Ultraviolet (BUV) measurements from Total Ozone Mapping Spectrometer (TOMS) flown on NASA's Nimbus - 7 satellite in 1978-1993. We apply TOMS ozone team calibration techniques and consistent MEaSUREs SO2 (MS_SO2) algorithm, to obtain the best measurement-based ESDR of volcanic and anthropogenic SO2 masses and emissions. As part of the NASA's Making Earth System Data Records for Use in Research Environments (MEaSUREs) program, the Goddard Earth Science (GES) Data and Information Data Center (DISC) has released a new SO2 Earth System Data Record (ESDR), TOMSN7SO2, re-processed using new 4 UV wavelength bands MS_SO2 algorithm that spans the full Nimbus 7 data period. TOMSN7SO2 is a Level 2 orbital swath product, which will be used to study the fifteen-year SO2 record from the Nimbus-7 TOMS and to expand the historical database of known volcanic eruptions. Sulfur Dioxide (SO2) is a short-lived gas primarily produced by volcanoes, power plants, refineries, metal smelting and burning of fossil fuels. Where SO2 remains near the Earth s surface, it is toxic, causes acid rain, and degrades air quality. Where SO2 is lofted into the free troposphere, it forms aerosols that can alter cloud reflectivity and precipitation. In the stratosphere, volcanic SO2 forms sulfate aerosols that can result in climate change.

Get the data

tomsn7so2_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="TOMSN7SO2",
    version="3",
    bounding_box=(-122.5, 37.2, -121.8, 37.9),  # your area (W,S,E,N)
    temporal=("2024-01-01", "2024-12-31"),       # your dates
)
files = earthaccess.open(results)   # stream straight from GES_DISC
Browsing CMR needs no login. Downloading or streaming bytes needs a free Earthdata Login + the earthaccess package.